CVE-1999-0702 in Internet Explorer
Summary
by MITRE
Internet Explorer 5.0 and 5.01 allows remote attackers to modify or execute files via the Import/Export Favorites feature, aka the "ImportExportFavorites" vulnerability.
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Analysis
by VulDB Data Team • 02/18/2025
The CVE-1999-0702 vulnerability represents a critical security flaw in Microsoft Internet Explorer versions 5.0 and 5.01 that exploited the Import/Export Favorites feature to enable remote code execution and file modification capabilities. This vulnerability emerged during a period when web browsers were rapidly evolving and becoming more integrated with local system operations, creating new attack surfaces that malicious actors could exploit. The flaw specifically targeted the way Internet Explorer handled favorites import and export operations, which were designed to allow users to transfer bookmark data between different browser installations or system configurations.
The technical implementation of this vulnerability stemmed from inadequate input validation and insufficient access controls within the Import/Export Favorites functionality. When users attempted to import favorites from external sources, the browser failed to properly sanitize the data being processed, allowing attackers to craft malicious favorite entries that could execute arbitrary code with the privileges of the running browser process. This weakness directly aligns with CWE-20, which describes improper input validation issues, and represents a classic example of how seemingly benign features can become attack vectors when proper security controls are omitted. The vulnerability essentially allowed attackers to bypass the normal security boundaries between the browser and the underlying operating system, creating a path for privilege escalation and persistent system compromise.
The operational impact of this vulnerability was significant, as it enabled remote attackers to execute malicious code on vulnerable systems without requiring user interaction beyond visiting a malicious website. This made the vulnerability particularly dangerous in the context of web-based attacks, where users might unknowingly navigate to compromised sites that contained the malicious favorites data. The ability to modify or execute files remotely meant that attackers could potentially install malware, modify system configurations, or establish persistent backdoors. From an attack framework perspective, this vulnerability mapped to multiple ATT&CK techniques including T1059 for command and scripting interpreter usage and T1068 for exploit for privilege escalation, demonstrating how browser-based vulnerabilities could be leveraged to achieve broader system compromise.
The exploitation of this vulnerability typically required attackers to craft specially formatted favorites files that would be processed by the vulnerable browser during import operations. These malicious files could contain embedded scripts or executable code that would be executed when the import process occurred, potentially leading to complete system compromise. The vulnerability highlighted the importance of secure coding practices and the need for comprehensive input validation even in features that appeared to be simple utility functions. Microsoft addressed this vulnerability through security updates that improved input sanitization and access controls within the favorites import/export mechanism, though the incident underscored the broader challenges of securing complex software applications that interact with local system resources. Organizations needed to implement immediate patch management procedures and educate users about the risks of visiting untrusted websites that might contain malicious favorites data.